US3115754A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mining shield
Assignee: Dowty Mining Equipment Ltd
•
Filing: 1959-01-23
•
Granted: 1963-12-31
•
Expires: 1979-01-23
Abstract
No abstract record available.
Inventors
- 👤 Hazel V Joseph
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:23
CPC Classifications
E; E21; E21D; E21D23/00; E21D23/0086; E21D23/0095; E21D19/00; E21D19/04; E21D23/08; E21D23/081; E21D23/082
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
96 words
A SHIELD FOR SUPPORTING THE ROOFS OF UNDERGROUND TUNNELS COMPRISING A PLURALITY OF CAGE TYPE ROOF SUPPORTING UNITS HAVING MEANS CONNECTING THEM AGAINST RELATIVE DETACHMENT FOR RELATIVE ADVANCEMENT AND RETRACTION AND OBLIQUE ANGLING WITH RESPECT TO EACH OTHER, POWER MEANS FOR INDEPENDENTLY ELEVATING AND LOWERING SAID UNITS WHEREBY EITHER OF THE UNITS MAY SUPPORT A ROOF WHILE THE OTHER IS LOWERED AND RELEASED FROM ROOF SUPPORT, AND POWER ACTUATED HYDRAULIC RAM MEANS FOR LONGITUDINALLY ADVANCING AND RETRACTING THE UNITS WITH RESPECT TO EACH OTHER, AND LATERALLY OBLIQUELY ANGLING OF THE SAME WITH RESPECT TO EACH OTHER.
Claim 2
Dependent Claim
96 words
A SHIELD FOR SUPPORTING THE ROOFS OF UNDERGROUND TUNNELS COMPRISING A PLURALITY OF CAGE TYPE ROOF SUPPORTING UNITS HAVING MEANS CONNECTING THEM AGAINST RELATIVE DETACHMENT FOR RELATIVE ADVANCEMENT AND RETRACTION AND OBLIQUE ANGLING WITH RESPECT TO EACH OTHER, POWER MEANS FOR INDEPENDENTLY ELEVATING AND LOWERING SAID UNITS WHEREBY EITHER OF THE UNITS MAY SUPPORT A ROOF WHILE THE OTHER IS LOWERED AND RELEASED FROM ROOF SUPPORT, AND POWER ACTUATED HYDRAULIC RAM MEANS FOR LONGITUDINALLY ADVANCING AND RETRACTING THE UNITS WITH RESPECT TO EACH OTHER, AND LATERALLY OBLIQUELY ANGLING OF THE SAME WITH RESPECT TO EACH OTHER.
References Cited (Backward Citations)
FR954897A
Cited
DE619297C
Cited
US2641906A
Cited
DE816237C
Cited
DE827051C
Cited
US2801522A
Cited
US2795936A
Cited
US2756034A
Cited
GB759647A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-12-30 | 1967-07-01 | 1967-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-12-30 | 1971-07-01 | 1971-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-12-30 | 1975-07-01 | 1975-12-31 | $7700.00 | Window Closed / Lapsed |